Questions for people who own or work in repair shops

This isn't specifically a repair question, but I thought those of you who do this professionally might have some insight on a situation I am dealing with.... I'd appreciate your insight. Thanks

I dropped my phone off at a local, highly rated repair shop at the end of january because the backlight stopped working. Other than that you could tell the phone was working fine... I still haven't gotten it back as of April 1. When I've called they say that they've done work on the phone but it still has "issues".... I realize phone fixes are not always easy. And I understand that they are busy, but it's been two + months. Am I out of line thinking that this is a bit ridiculous?

My other question is, if this shop does not fix the problem, how do I know they have not caused further damage to my device attempting repairs after telling me they could fix it? What would you do in this situation if it was your business?

after this long I'm getting nervous and feeling very unprotected